driveline vibration t5 swapped 7/9xx 1pc driveline

driveline vibration t5 swapped 7/9xx 1pc driveline - with solution

So here's the deal. Goldie, my '92 940 project car got a t5 swap last july and has been plagued with problems since.

Relevant parts list:
flat flywheel, 8.5" spec s2+ clutch kit - it's not rpm dependent anyhow
solid under-drive pulley
Solid rubber 740 motor mounts

Rebuilt T5 (also tried a second borrowed T5 which didn't change anything)
modified aw71 x-member
energy poly trans mount

54.5" 3" DOM tube driveline (balanced)
new fancy spicher 1330 rear u-joints
used mustang slip yoke and 1350 u-joint
no play in either u-joint

full Kaplhenke rear end (subframe, tq rods, ph bar)
spherical bearings on tq rods, and panhard bar

freshly rebuilt 1041 rear end
new bearings shims and seals
axle shafts checked for balance and straightness

Pinion angle is set to 2.5 deg down at the trans and 2.5 deg up at the pinion. So they are equal and opposite with 2.5deg of working angle for the u-joints. I do not know how I can measure the side to side alignment, I'm just assuming that since it's in the center of the tunnel it's all good.
this is one of the sites i used to learn how to set a pinion angle:
http://jniolon.clubfte.com/drivelinephasing/drivelinephasing.html

Vibration tests were done with car up in the air (on the suspension), wheels, brake rotors and e-brake removed. So it's just the axle, driveline, trans, and engine spinning. Road tests have the similar results, with 2 sets of wheels and tires. RPM determined with 1:1 4th gear and speed on 3.73:1 rear end gear, 24.9" tires.

The symptom:

At 3200 rpm driveline speed (~60mph) I get a strong driveline vibration. I can visually see the driveline move up and down as it spins, and using applying a scribe slowly to the spinning driveline it will chatter and mark about 2" of the circumference of the driveline.
I didn't setup a dial indicator to measure how much deflection there is.

The vibration is felt strongly in the car up to about 4600rpm driveline speed (~90mph) where is smooths out.

I'm running out of options, i've rebuilt the trans, the rear end, and replaced all the motor and trans mounts. I've tried several different pinion angle combos, including raising the trans so that it's pointing up, and lowering the pinion. The driveline has been back to the driveline shop 2 times and each time they tell me that's it's perfect and that it spins up beautifully. They don't however include the slip yoke in the balancing.

I'm going to have them install a new front u-joint and a new slip yoke tomorrow. With those replaced, I don't know where else to turn.

What have I overlooked? How likely is it that there is a lateral pinion offset, and how can I check that?

Thanks for the help guys. I'm real close to scrapping the 1pc and going to a 2 piece.


Here's another good trans vibration thread:
http://forums.turbobricks.com/showthread.php?t=217894

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The FIX:

As per Nathan's suggestion I checked out my bellhousing alignment.

First numbers were scary to say the least over .030 or 10x the allowed misalignment.
http://i483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/T5 Swap/Photo440.jpg



I rearranged the dial indicator to be more accurate and measured that it was still .010 out, so more matterial removed.
http://i483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/T5 Swap/Photo442.jpg

Getting closer:
http://i483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/T5 Swap/Photo443.jpg

How I aligned it was to clearance the opening in the bellhousing and slipping the adapter down.
http://i483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/T5 Swap/Photo444.jpg



A few more passes with the emery cloth, and a few more refittings and remeasurings I eventually got it close enough. The spec being passed around is .004" misaligned. I'm happy with .002"
http://i483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/T5 Swap/Photo445.jpg


Since the adapter was no longer interference fit into the bellhousing again as per Nathan's suggestion I decided to pin the adapter in place by drilling and threaded 2 7/16" bolts through the bellhousing and into the adapter.

I used an end mill to make 2 flat spots on the bellhousing.
http://i483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/T5 Swap/Photo450.jpg

http://i483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/T5 Swap/Photo449.jpg

Drilled and tapped some holes.
http://i483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/T5 Swap/IMG_0628.jpg


And bolted it down:
http://i483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/T5 Swap/IMG_0621.jpg

http://i483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/T5 Swap/IMG_0619.jpg


I also changed the tail housing of the T5 for another unit that had a significantly wider tailshaft bushing. The new bushing was only .750" wide where the old one from this other box was 1.25" wide so I figured it may help stabilize the slip yoke.

So that's the story, I got it all installed, dialed in 1.5deg of pinion offset on the driveline and ran it up on the jackstands. Ran real smooth well past 130mph will very little vibration at the problematic 65mph range. Put it on the ground and drive it, and god dam it drives like a regular 5 speed, not a car trying to shake itself apart. Simply amazing.

So thanks everyone for their help and support. I hope no one runs into issues like this, but if they do I hope that this will help them remedy it with less hassle.

as always pics an be found here:
http://s483.photobucket.com/albums/rr191/Magnumte/Volvo/Goldie/

EDIT:
I added some Lucas heavy duty oil stabilizer about 10-16oz (basically until my hands got wore out from squeezing the bottle to feed it up the tube into the trans) and much of the gear noise has quieted down. I don't need to wear ear plugs on the freeway anymore.

Is the driveshaft timed?

You may have to much angle at the rear joint, if you have 2.5 at the trans and are starting with 2.5 at rest that 2.5 will increase under load, you may want to bring the 2.5 down to 2.0 depending which suspension you have

The issue you are describing sounds as if the shaft wasn't high speed balanced.... Are you sure the shaft is at 3200 rpm, when you are reading that rpm what gear are you in? what is that gears ratio .

Most balancing machines do not go to 3000 rpms, many are dynamic and spin at 500 rpm and guesstimate whats happening after that.
2 machines go to 3500 rpm and 2 machines go beyond that, I believe you need to have the shaft rebalanced...

Do not look at the shaft in the car and figure it's not true or bent, when you look at the shaft it is working thru angles and as the shaft spins the joints are going thru different phases and or oscillating and that moves the shaft forward and back and appears as if it's AFU.

Someone unwittingly installed the 'DL Driveshaft rumble' in his 240!

When we put the Jerico in the rallycar we considered a one piece driveshaft and figured that Volvo likely had a damned good reason for why they did it in two pieces..... The two piece driveshaft in the rallycar ended up utterly smooth. We did go to some effort with verifying that the crankshaft and driveshaft are in a straight line for the first half of it.

I've been fighting with the DL driveshaft rumble in 'The Penalty Box' and am annoyed with it.

Also when you say 62" in the driveline world that measurement will be figured on the center of the joint in the weld yokes, and at 62" on center you're rpm limited with that stl shaft to around 4800/4900.

I just seen this part about the slip yoke, the SLIP yoke MUST be balanced with the shaft, there is your problem

Who's slip yoke are you using ?

Thanks for the responses guys. I will look into the suggestions.

dieselboy said:

Is the driveshaft timed?

Click to expand...

Not sure what that means, but I will ask the driveline shop tomorrow. The U joints are squared to each other, if that's what timed means.

Supershafts said:

You may have to much angle at the rear joint, if you have 2.5 at the trans and are starting with 2.5 at rest that 2.5 will increase under load, you may want to bring the 2.5 down to 2.0 depending which suspension you have

The issue you are describing sounds as if the shaft wasn't high speed balanced.... Are you sure the shaft is at 3200 rpm, when you are reading that rpm what gear are you in? what is that gears ratio .

Most balancing machines do not go to 3000 rpms, many are dynamic and spin at 500 rpm and guesstimate whats happening after that.
2 machines go to 3500 rpm and 2 machines go beyond that, I believe you need to have the shaft rebalanced...

Do not look at the shaft in the car and figure it's not true or bent, when you look at the shaft it is working thru angles and as the shaft spins the joints are going thru different phases and or oscillating and that moves the shaft forward and back and appears as if it's AFU.

Click to expand...

The solid bushings in the rear don't allow for much axle travel, and it makes the vibration with no load (up in the air with no tires and brakes). I will keep that in mind when I reinstall the driveline. Like I stated earlier, I've tried a lot of combinations, from 3 deg down, to 3 deg up in about 1 deg increments.

I did forget to add that the driveline rpm was in 4th gear which is 1:1 rear end gear is 3.73 tire height is 24.9" (I'll add that to my initial post)

They told me they would call me when they chucked the driveline up in the balancer so I could come watch. I'll ask how many rpm it spins.

The shaft seems like it's egg shaped when it's spinning at the front but it's completely round at the rear, ie: not moving around.

Supershafts said:

Also when you say 62" in the driveline world that measurement will be figured on the center of the joint in the weld yokes, and at 62" on center you're rpm limited with that stl shaft to around 4800/4900.

I just seen this part about the slip yoke, the SLIP yoke MUST be balanced with the shaft, there is your problem

Who's slip yoke are you using ?

Click to expand...

The slip yoke and the front U-joint are from a donor Mustang. The driveline shop told me they take the slip yoke off and balance it with just the u-joints that are welded to the driveline.

As far as rpm limit, that's what the spicer site says, the driveline shop said they have people pushing them a lot faster than that. I don't remember what the driveline length actually is, but it's long as **** so a number ROMA 62" is close enough. The important thing is that it's the proper length and the slip yoke lives about 1" from the trans at full compression and just about 2" at full drop.

Thanks for the suggestions. My finger's are crossed about tomorrow, I hope to get to the bottom of this.

JohnLane said:

Someone unwittingly installed the 'DL Driveshaft rumble' in his 240!

Click to expand...

it's a 940, and it's way more rumblely than that, feels like it's trying to escape

also, it's not close to rubbing on anything, I painted the driveline tunnel a contrasting color and there are no marks anywhere on the driveline.

You just COMPLETELY described my issue Toby...along with my findings...which I will soon fix.

I've had the 2-piece on the wagon rebalanced 3 times, by a guy who REALLLLLY knows his stuff. After finding the center bearing was not truly round (.005" off, new one made a big difference), that helped, BUT I'm still fighting a vibration from 45-65mph.

Now for the findings...I have play in the tailshaft bearing on the AW71, amounting to around .020-.030", so you can see the yoke move in the trans slightly, making it appear the driveline isn't straight. Diff is perfectly smooth and round. Hopefully a new bearing should help.

I had a similar issue on the W50 in the 140 that has a slip-yoke and 1pc. Found the shop that did the rebuild forgot to replace the tailshaft housing bushing (amongst other things that led to a court appearance). The shop that actually did a legit rebuild put a new bushing in that's pretty snug and that settled things down a bit.

Might check how much lateral play you have in the yoke as close to the trans as you can measure, that might be part of your issue.

Magnum TE said:

Thanks for the responses guys. I will look into the suggestions.



Not sure what that means, but I will ask the driveline shop tomorrow. The U joints are squared to each other, if that's what timed means.

Click to expand...

Thats called phasing, not time, the yokes on the shaft need to be on the same plane

I did forget to add that the driveline rpm was in 4th gear which is 1:1 rear end gear is 3.73 tire height is 24.9" (I'll add that to my initial post)

They told me they would call me when they chucked the driveline up in the balancer so I could come watch. I'll ask how many rpm it spins.

The shaft seems like it's egg shaped when it's spinning at the front but it's completely round at the rear, ie: not moving around.


The slip yoke and the front U-joint are from a donor Mustang. The driveline shop told me they take the slip yoke off and balance it with just the u-joints that are welded to the driveline.

Click to expand...

The shaft should have been MADE and trued with the slip yoke and then balanced with the slip yoke, the slip yoke can be off up to .003 from center which if it's not on the shaft when balanced it will affect the balance.

Just get the name off the machine when you see it i'll know from that what it's capabilities are.

The shaft needs to be balanced with all the parts on it, if it uses a flange the flange needs to be on the shaft, slip yokes, and 2pc shafts need to all be assembled as they are in the car and then balanced.
Definitely in the balancing i go thru this with many other shops


When you get the shaft back measure from center to center on the joints.

.
gsellstr you have the same situation 45 to 65 and then it gets better , if so you need to have the shaft balanced again by a shop capable of doing it.

Don't let these shops do these in stl, use AL for these conversions. . .

If the shaft breaks at critical speed YOU will be in serious serious trouble and it very well WILL cut thru the car and YOU could die. .

.

The 2-pc. stock shaft on mine has actually been on a high-speed balancer, by a shop that knows what they're doing. It's also balanced with all parts intact, but the play in the tailshaft of the trans itself isn't helping anything on mine. You can actually feel the vibration on the trans, less at the carrier, and none at the diff as well.

The 140 is actually a steel 1pc, but 3" tube to handle the speed and length, and the only issues it has at this point are trans related, and nothing critical, just an archaic old design trans...

It's a little late for me to have it made in Al. Thanks for the info Supershafts, i'll see if I can get the model of their machine.

edit: driveline length is 54.5" from the center of the U-joints, he told me that 75% critical speed should be about 4000rpm

The balance machine they use goes up to 4000rpm. I didn't get a model number. It does not however accommodate the slip yoke, so it's just the driveline side of the front u-joint, in the rear the pinion flange is left on the driveline.

The guy told me that there was a little bit of buzz at 4k so he put a new weld yoke on the front. With the new yoke he was able to reduce the balance weight by half so that could be it.

I saw it run in the machine, and it was really freaking smooth, but the guy tells me that it was pretty smooth before so meh.

I'm also trying a different slip yoke.

Did you get anymore testing done? My shaft was 54 inches lines, 3x.083. Balances out and my ujoint stuck out about 4 inches from the tranny. I matched working angles like you and was golden.

Without the slip yoke being apart of the assembly when it's balanced there is going to always be a issue somewhere within the range of use.
The slip yokes aren't perfectly machined for equal weight and sometimes they're slightly off center.

At 54.5" you should be ok to 6000rpm if it's .083 wall tube.

Hopefully it's better, if not you're going to have to find a shop that can balance it with the slip yoke

Supershafts said:

Without the slip yoke being apart of the assembly when it's balanced there is going to always be a issue somewhere within the range of use.
The slip yokes aren't perfectly machined for equal weight and sometimes they're slightly off center.

At 54.5" you should be ok to 6000rpm if it's .083 wall tube.

Hopefully it's better, if not you're going to have to find a shop that can balance it with the slip yoke

Click to expand...

That doesn't seem so good - how fast is 6000rpm in 4th gear? I would always try to have a DS rated for whatever the redline of the motor is in 4th gear personally... especially in Nathan's case since he has a 6 speed, double overdrive tranny and presumably a short rear end.

I went back to a 2pc. Still the same 3 inch shaft x .083 wall stuff. Reason was suspension travel was limited with 1pc, and crtical speed was around 5800 iirc, and with the potential of running 7500rpm in 4th in the 1/4 mile, this scared me. So now my 2 shafts are good for like 11,000 rpm, and I have my travel back.

When I had the 1pc, I must have gotten lucky, cuz I installed my slip yoke here at the house before assembly.

Well im just letting him know, always better to use AL shafts, AL is usually in most cases another 1000 rpm more before you have a catastrophic failure at the same length compared to stl

Nathaninwa said:

I went back to a 2pc. Still the same 3 inch shaft x .083 wall stuff. Reason was suspension travel was limited with 1pc, and crtical speed was around 5800 iirc, and with the potential of running 7500rpm in 4th in the 1/4 mile, this scared me. So now my 2 shafts are good for like 11,000 rpm, and I have my travel back.

When I had the 1pc, I must have gotten lucky, cuz I installed my slip yoke here at the house before assembly.

Click to expand...

But now you slowed yourself down, this is why the factory uses the smaller tube and lighter.

The weight of that 2pc now is slowing you.

How do you figure you lost travel with a 54" 1 pc vs a 2 pc with a hanger that is actually going to have less travel?

Supershafts said:

But now you slowed yourself down, this is why the factory uses the smaller tube and lighter.

The weight of that 2pc now is slowing you.

How do you figure you lost travel with a 54" 1 pc vs a 2 pc with a hanger that is actually going to have less travel?

Click to expand...

I have such a beefy driveline including 1350 joints and forged yokes, because Ill have close to 700whp and launch control and antilag. Ill leave the line around 5500 to 6000rpm, where ever the rear tires wont break lose.

I lost travel because the 7/9 series cars have a factory driveshaft loop under the back seat area limiting overall travel. I had to weld on 1 inch bump onto the rearend so I wouldnt hit shaft under compression, and limiting straps to stop the driveline from becoming a balance point when your changing tires, or unload the suspesion crowning hills at speed.

I left it to the driveline shop to make what I needed to handle the power.

the driveshaft loop on that model is at the wrong end, should have removed that.

700hp in a 2pc could have been done in 2" .095 and the rpm works also, im surprised launching like that you aren't having hanger issues

Its not really a loop, its part of the chassis design. Not sure what I would call it really.

Check out the last couple pages of my build thread(in sig), youll see the rearend setup is not really stock anymore.